As fathers throughout Britain open their cards on Sunday morning, imagine this. You and your family are sitting down to a meal when you hear gunshots. Moments later, you’re surrounded by militia pointing AK47s. You, the father, are given a choice: “We either rape your daughter or kill your son. You decide.” Roa, the daughter of the man this happened to, was four at the time.

The UN has recognised rape as a deliberate weapon of war in Sudan since 2005. Yet, it steadfastly fails to provide adequate protection for the victims or consequences for the perpetrators. Angelina Jolie, a UN special envoy, and William Hague co-chaired a summit in London last week to end sexual violence in conflict. Roa and her family could not be there.

Driven from their homes and their livelihoods, they, like an estimated four million others, sought refuge in a displaced persons camp. But as Sudan’s government persistently obstructs humanitarian aid to the camps, Roa’s nightmare is far from over.

Every day, women and children in Darfur, in western Sudan, face the prospect of being raped. Leaving their homes and camps to find food and firewood is hazardous. It is where more than 80 per cent of the rapes occur.

Some women refuse medical help after being raped and hide their ordeal to spare their family. Others are “branded” by their attackers so that they will never be free from “shame”. Rape is an integral, strategic component of the genocide in Darfur. Women and children are routinely raped in front of their families, breaking minds as well as bodies, in the attempt to crush their wills and erode family structures in which chastity are sacrosanct.

A few years ago, I co-organised a series of global demonstrations for Darfur. One focused entirely on rape as a weapon of war. We asked the women in the camps what the international community could do to help.

They wanted whistles so that they could raise the alarm if attacked while foraging for firewood. Citizens around the world simultaneously demonstrated outside their parliaments, blowing whistles. We also asked for more UN peacekeepers to protect civilians, for groups of policewomen from African nations to accompany the firewood-gathering trips, for rape counselling and increased medical treatment for sexually transmitted diseases.

Seven years on, there’s no sign of the African policewomen, and efforts to provide medical treatment and counselling have been obstructed by the Sudanese government. More peacekeepers have been deployed to the region, with a mandate to protect civilians, yet the raping rampage continues undeterred. We blow our whistles, said one woman, but no one comes.

The promises made at the London summit last week must be kept. We owe Roa that.